Skip to main content

Before applying for CfA Telescope time, please check telescope and instrument availability below. Before applying for a PI instrument, contact the Principal Investigator and obtain a letter of approval to be submitted with your proposal.

First time users are expected to read the documentation and speak with the instrument PI if they have questions; the TAC chair can point people to recent users for practical tips.

COVID-19 update: The observatories have mostly returned to normal operations but travel restrictions remain, which impacts PI instruments. The TAC encourages proposals for instruments that can be operated in service-observing, queue, or remote-observing modes, which is essentially every instrument except M2FS, PISCO, and MagAO.


  • 6.5m MMT telescope, located on Mt Hopkins in Arizona. Approximately 26 dark + 13 grey + 26 bright nights are available per 6 month semester; summer shutdown impacts July and August.

  • 6.5m Magellan telescopes, located on Las Campanas in Chile. Approximately 21 dark + 11 grey + 21 bright nights, evenly split between the two telescopes, are available per 6 month semester. Instruments are linked to a specific telescope.

  • Fred Lawrence Whipple Observatory (FLWO), located on Mt Hopkins in Arizona. The 1.2m telescope is dedicated to imaging; the 1.5m telescope is dedicated to spectroscopy. Approximately 72 dark + 36 grey + 72 bright nights are available on each telescope per 6 month semester, minus 30 nights in B semester due to August shutdown.


  • MMT and FLWO instruments are mostly run in queue mode, as indicated below. For instruments run in a queue, PI's submit their targets before the scheduled observing run; observations are obtained by observers at the telescope.
  • Magellan instruments, with two exceptions, are not queue-scheduled. That said, a service observer is now available to CfA PIs; travel to Magellan is no longer required. The expectation is that the service observer will do the observing unless PIs choose otherwise.


1.2m FLWO Available? Queue?
Optical KeplerCam - CCD imager YES YES
1.5m FLWO Available? Queue?
Optical FAST - moderate dispersion single-slit spectrograph YES YES
  TRES - high dispersion single-fiber echelle spectrograph YES YES


6.5m MMT Available? Queue?
Optical Binospec - moderate dispersion multi-slit spectrograph and imager YES YES
  Hectospec - moderate dispersion 300-fiber spectrograph YES* YES
  Hectochelle - high dispersion 240-fiber echelle spectrograph YES* YES
  Blue Channel - moderate dispersion single-slit spectrograph YES no
  MMT Cam - small field-of-view imager YES YES
  SPOL - imaging spectropolarimeter Contact PI no
Near-IR MMIRS - multi-slit spectrograph and imager YES YES
  ARIES - adaptive optics imager and spectrograph no** no
  MMT-Pol - imaging polarimeter no** no

* Hectospec/chelle are not scheduled in Dec-Jan because of a low-temperature operational limit.

** MMT Adaptive Optics System is offline for upgrades; it is not expected to be available for proposals until 2023.


6.5m Magellan I = Baade Available? Queue?
Optical IMACS - moderate dispersion multi-slit spectrograph and imager YES no
  MagE - moderate dispersion single-slit echellette spectrograph YES no
Near-IR FourStar - wide-field imager YES no
  FIRE - high dispersion single-slit echelle spectrograph YES no
6.5m Magellan II = Clay    
Optical Megacam - wide-field imager YES no
  LDSS-3 - moderate dispersion multi-slit spectrograph YES no
  MIKE - high dispersion single-slit echelle spectrograph YES no
  M2FS - fiber fed multi-object spectrograph (planning) (reductions) Contact PI* YES
  PFS - high dispersion single-slit echelle spectrograph Contact PI YES
  PISCO - parallel imager no no
Near-IR MagAO - adaptive optics imager(s) Contact PI no

* Depends on travel restrictions.

[Updated Sept 10, 2021 by WRB.]